Stromal upregulation of SOX2 promotes tumorigenesis through the generation of a SFRP1/2-expressing cancer-associated fibroblast population [Quant-seq]
Ontology highlight
ABSTRACT: Although how CAFs impact the tumor epithelium is being progressively unveiled, transcriptional processes of lineage plasticity in fibroblasts govern the acquisition of the CAF phenotype are much less understood. Here we show that the upregulation of SOX2 is a critical step in this process, which is negatively regulated by the atypical protein kinase (aPKC) PKCz. We demonstrate that the loss of PKCz is essential for the acquisition of the CAF phenotype and for the induction of the desmoplastic and more aggressive phenotype of intestinal tumors in a SOX2-dependent manner. Furthermore, we show here that the loss of PKCz drives the reprogramming of colon stromal fibroblasts into two different subpopulations that express either the Wnt regulators Sfrp1/2 or osteopontin, both ligands positively impinging into the mesenchymal and stem cell activation programs.
Project description:Although how CAFs impact the tumor epithelium is being progressively unveiled, transcriptional processes of lineage plasticity in fibroblasts govern the acquisition of the CAF phenotype are much less understood. Here we show that the upregulation of SOX2 is a critical step in this process, which is negatively regulated by the atypical protein kinase (aPKC) PKCz. We demonstrate that the loss of PKCz is essential for the acquisition of the CAF phenotype and for the induction of the desmoplastic and more aggressive phenotype of intestinal tumors in a SOX2-dependent manner. Furthermore, we show here that the loss of PKCz drives the reprogramming of colon stromal fibroblasts into two different subpopulations that express either the Wnt regulators Sfrp1/2 or osteopontin, both ligands positively impinging into the mesenchymal and stem cell activation programs.
Project description:Although how CAFs impact the tumor epithelium is being progressively unveiled, transcriptional processes of lineage plasticity in fibroblasts govern the acquisition of the CAF phenotype are much less understood. Here we show that the upregulation of SOX2 is a critical step in this process, which is negatively regulated by the atypical protein kinase (aPKC) PKCz. We demonstrate that the loss of PKCz is essential for the acquisition of the CAF phenotype and for the induction of the desmoplastic and more aggressive phenotype of intestinal tumors in a SOX2-dependent manner. Furthermore, we show here that the loss of PKCz drives the reprogramming of colon stromal fibroblasts into two different subpopulations that express either the Wnt regulators Sfrp1/2 or osteopontin, both ligands positively impinging into the mesenchymal and stem cell activation programs.
Project description:Although how CAFs impact the tumor epithelium is being progressively unveiled, transcriptional processes of lineage plasticity in fibroblasts govern the acquisition of the CAF phenotype are much less understood. Here we show that the upregulation of SOX2 is a critical step in this process, which is negatively regulated by the atypical protein kinase (aPKC) PKCz. We demonstrate that the loss of PKCz is essential for the acquisition of the CAF phenotype and for the induction of the desmoplastic and more aggressive phenotype of intestinal tumors in a SOX2-dependent manner. Furthermore, we show here that the loss of PKCz drives the reprogramming of colon stromal fibroblasts into two different subpopulations that express either the Wnt regulators Sfrp1/2 or osteopontin, both ligands positively impinging into the mesenchymal and stem cell activation programs.
Project description:Although how CAFs impact the tumor epithelium is being progressively unveiled, transcriptional processes of lineage plasticity in fibroblasts govern the acquisition of the CAF phenotype are much less understood. Here we show that the upregulation of SOX2 is a critical step in this process, which is negatively regulated by the atypical protein kinase (aPKC) PKCz. We demonstrate that the loss of PKCz is essential for the acquisition of the CAF phenotype and for the induction of the desmoplastic and more aggressive phenotype of intestinal tumors in a SOX2-dependent manner. Furthermore, we show here that the loss of PKCz drives the reprogramming of colon stromal fibroblasts into two different subpopulations that express either the Wnt regulators Sfrp1/2 or osteopontin, both ligands positively impinging into the mesenchymal and stem cell activation programs.
Project description:Tumor microenvironment is a strong determinant for the acquisition of metastatic potential of cancer cells. It has been demonstrated (Giannoni E et al., Cancer Res 2010) that cancer associated fibroblasts (CAF) elicit an epithelial-mesenchymal transition (EMT) in prostate cancer (PCa) cells, leading to enhanced tumor cell aggressiveness. Here, we investigated the involvement of microRNAs (miRNA) in such malignant tumor-stroma interplay, to identify possible tools to counteract metastasis dissemination. To verify whether specific miRNAs are involved in CAF-induced EMT in PCa cells, PC-3 cells were subjected to a variety of stimuli, known to induce or not the acquisition of a mesenchymal phenotype (Giannoni E et al., Cancer Res 2010; Giannoni E et al., Antioxid Redox Signal 2011) , and profiled for miRNA expression on a microarray platform. miRNA expression profiles successfully distinguished cells that underwent EMT following the stimulation with activated fibroblasts (here referred to as “mesenchymal”) from cells that did not (“epithelial”).
Project description:Although how CAFs impact the tumor epithelium is being progressively unveiled, transcriptional processes of lineage plasticity in fibroblasts govern the acquisition and transition of the CAF phenotype are much less understood. Here, to explore the potential involvement of the circular RNAs (circRNAs) in fibroblast activation and phenotype acquisition, we isolated CAFs and NFs from human pancreatic cancer and paired normal pancreatic tissue. Next, we conducted circRNA profiling five CAFs and three paired NFs by high throughput sequencing. Our results showed that clusters of circRNAs were aberrantly expressed in CAFs compared with NFs, and provided potential targets for future treatment of PDAC and novel insights into PDAC microenvironment.
Project description:During development, specialized cell lineages are generated through the establishment of cell type-specific transcriptional patterns and epigenetic programs. However, the precise mechanisms and regulators that maintain these specialized cell states remain largely elusive. To identify molecules that safeguard somatic cell identity, we performed two comprehensive RNAi screens targeting known and predicted chromatin regulators during transcription factor-mediated reprogramming of mouse fibroblasts to induced pluripotent stem cells (iPSCs). Remarkably, subunits of the chromatin assembly factor-1 (CAF-1) complex emerged as the most prominent hits from both screens, followed by modulators of lysine sumoylation, DNA methylation and heterochromatin maintenance. Suppression of CAF-1 increased reprogramming efficiencies by several orders of magnitude and generated iPSCs two to three times faster compared to controls without affecting cell proliferation. We demonstrate that suppression of CAF-1 leads to a more accessible chromatin structure specifically at enhancer elements early during reprogramming. These changes were accompanied by increased binding of the reprogramming factor Sox2 to ESC-specific regulatory elements and earlier activation of pluripotency-associated genes. Notably, suppression of CAF-1 also enhanced iPSC formation from blood progenitors as well as the direct conversion of B cells into macrophages and fibroblasts into neurons. Together, our findings reveal the histone chaperone CAF-1 as an unanticipated regulator of somatic cell identity and provide a potential strategy to modulate cellular plasticity in a regenerative setting. Keywords: Genome binding/occupancy profiling by high throughput sequencing Chromatin accessibility and Sox2 bindings in CAF-1 knockdown and Renilla control during early OKSM reprogramming by high throughput sequencing
Project description:Cellular differentiation involves profound changes in the chromatic landscape, yet the mechanisms by which somatic cell identity is subsequently maintained remain incompletely understood. To further elucidate regulatory pathways that safeguard the somatic state, we performed two comprehensive RNAi screens targeting chromatin factors during transcription factor-mediated reprogramming of mouse fibroblasts to induced pluripotent stem cells (iPSCs). Remarkably, subunits of the chromatin assembly factor-1 (CAF-1) complex emerged as the most prominent hits from both screens, followed by modulators of lysine sumoylation and heterochromatin maintenance. Suppression of CAF-1 increased reprogramming efficiency by several orders of magnitude and facilitated iPSC formation in as little as 4 days. Mechanistically, CAF-1 suppression led to a more accessible chromatin structure at enhancer elements early during reprogramming. These changes were accompanied by a decrease in somatic heterochromatin domains, increased binding of Sox2 to pluripotency-specific targets and activation of associated genes. Notably, suppression of CAF-1 also enhanced the direct conversion of B cells into macrophages and fibroblasts into neurons. Together, our findings reveal the histone chaperone CAF-1 as a novel regulator of somatic cell identity during transcription factor-induced cell fate transitions and provide a potential strategy to modulate cellular plasticity in a regenerative setting. Gene expression analysis in CAF-1 knockdown and Renilla control during early OKSM-induced reprogramming by microarray
Project description:To clarify the molecular alterations triggered by miR-9 to induce the conversion of breast normal fibroblasts to a CAF-phenotype, gene expression profile of normal fibroblasts transiently transfected with miR-9 or control was performed.
Project description:Carcinoma-associated fibroblasts (CAF) are key players in the tumor microenvironment. By combining 6 well-known stromal markers, we identify four CAF subsets (CAF-S1 to CAF-S4) in human breast and ovarian cancers.